Slip clutch



Umted States Patent 1111 3,545,584

[72] Inventor Victor Taltata [56] References Cited cambfldsei Massachusetts UNITED STATES PATENTS P 23 1,265,271 5/l9l8 Snyder l92/88(A)UX [221 PM 1 2,020,640 11/1935 Guenther l92/88(A)UX [45] Patented Dec. 8, 1970 Assignee Artisan Industries Inc 2,432,272 l2/l947 Banff |92/88(A)X 9 wanhamMassachusem 2,633,6 7 4/1953 Johnson l92/88(A)X a corporation of Massachusetts Primary Examiner- Allan D. Herrmann Original a lleaflon Sept. 12, 1966, s Attorney-Richard L. Cannaday No. 578,768, now Patent No. 3.475.945.

ABSTRACT: A bellows-type slip clutch for use in association with and as part of the drive system of a rotatable shaft, for example, a shaft carrying film spools in an apparatus for processing striplike photographic film, this clutch being adapted to receive rotational driving impulse from a prime [54] Sup CLUTCH mover and to have its bellows element expand under pressure 2 n 9 Drawing Figs and contract through resiliency with changes in fluid pressure [52] U.S. Cl. 192/88, signals to increase and decrease correspondingly its frictional l92/ 103 driving engagement with said shaft through a pressure plate [5|] Int. Cl Fl6d 19/00 freely rotatably mounted on the shaft and turned by the prime [50] Field of Search l92/85(A3), 88(A), l03(F); mover and a friction disk axially movably but nonrotatably 188/] 52.86(A) mounted on the shaft.

l2l 5 l2! PATENTED DEC 8 I970 sum 1 or 2 All ' INVEN'IOR.

' VI A :1 BY CTOR TAK AT ATTORNEY PATENTEU 0E1: BIBYB 3.545584 SHEET 2 BF 2 INVENTOR. m VICTOR TAKATA ATTORNEY SLIP CLUTCH BACKGROUND OF THE INVENTION In the processing of a strip interval exposed motion picture film it is most important that a very accurate timewise exposure or contact of the film material with the various processing materials and solutions bemaintained. Currently used high-- speed and color films require in their processing or developing steps certain treatments which are particularly noted as being of very short duration, for example, only a few seconds. Certain other steps of greater duration likewise require that the treatment time interval be closely regulated. As the reels of exposed film are usually several'hundred feet in length, the most practical manner of processing is to feed the film in a continuous manner through a multiplicity of tanks in which each of the processing reactions may be precisely controlled. During processing it is highly desirable that the emulsion side of the film be free of contact with anything but the materials or chemicals used in the steps of developing. It is also to be borne in mind that the damp or wet film may be subject to unwanted stretching if undue or excessive tension is imposed upon it as it is transported through the various processing steps.

Automatic processing of film has been practiced for a number of years. Known apparatus for this practice includes banks of spools carried on upper and lower shafts. The spools are arranged to transport the film in a helical manner. Included in one of the known processing systems is apparatus in which theupper and lowerspool-carrying shafts are in fixed relationship to each other with at least some of the spools on thelower shaft being driven so as to provide surface speeds in excess of the desired film speed. This method anticipates that film traveling a little too fast will bulge slightly from the determined path causing a slight reduction of the overall contact force of the film upon the driving spool or spools and slowing the film. If the film travels a little too slowly it does not bulge but engages the spool with a relatively greater overall contact force so as to increase its, the film's, speed. In other known systems vertically movable lower shafts are used and the speed of the film is regulated by employing an intermittent drive or by passing the film over drive spools of successively varying sizes. Still another known system utilizes a fixed sprocket on each shaft of the bank. As long as the size, type and sprocket engaging apertures of the film are the same this method of antomatic processing is satisfactory, but necessarily has only very limited flexibility.

The present invention relates to an apparatus and method for film processing and the like in which film is fed to at least one bank of. spools having an upper shaft and a lower shaft. The lower shaft is carried by an elevator having a means for actuating a flow control valve in response to the reciprocation of the elevator. The flow control valve modulates a flow of pressurized air, gas, or liquid, or the application of a vacuum to the interior of a clutch, spool or chamber to increase of decrease the speed of film. Theflow control valve may be connected to apparatus in the same or different banks of spools. According to the inventive concepts hereinafter more fully described, variations in the tension in the strip of film being transported through the bank are used to raise and lower the elevator. Thus since the film being transported is accelerated or decelerated in response-to the movement of the elevator as stated above, it is also and ultimately accelerated or decelerated according to its own tension varying either side of a normal value.

It is therefore an object of this invention to provide an apparatus for and a method of modulating the speed of traveling material of striplike form, the modulation being responsive to the tension in the material.

It is a further object of this invention to provide an apparatus for and a method of modulating the speed and tension of a traveling film strip disposed in a helix around spools carried on upper and lower shafts, the lower shaft being mounted on an elevator movable responsively to the tension of the traveling film, the elevator movement actuating a flow control valve adapted to accelerate or decelerate the film drive means or, most desirably, hold it in an essentially steady running condition.

It is a further object of this invention to provide apparatus for and'a method of modulating the speed of a traveling film strip which is disposed in a helix around spools carried on. upper and lower shafts, the lower shaft being mounted on an elevator movable responsively to the tension of the film strip and the elevator movement actuating a flow control valve adapted to transmit a fluid pressure signal or effect including a vacuum effect or signal, to'actuate a clutch to accelerate or decelerate the spools carrying the traveling film.

These and other objects and advantages of the present invention as well as its nature and substance will be more clearly perceived and fully understood by referring to the following description and claims taken in connection with the accompanying drawings in which:

FIG. 1 represents a sectional side view of a typical film processing tank equipped with a modulating drive assembly representative of the present invention;

FIG. 2 represents a fragmentary sectional plan view showing a portion of an elevator mechanism taken along line 2-2 in FIG. 1 looking in the direction of arrows:

FIG. 3 represents a sectional side view of a modulating drive flow control valve;

FIG. 4 represents a sectional side view of a bellows-type slip clutch adapted for use with'and responsiveness to a flow control valve;

FIG. 5 represents a plan view of a retaining ring used in the bellows-type clutch of FIG. 4;

FIG. 6 represents a fragmentary sectional view showing the spring hook of the retaining ring of FIG. 5 taken along line 5-5 therein looking in the direction of the arrows;

FIG. 7 represents a fragmentary sectional side view of a modulating drive including a sprocket drive and bellows-type slip clutch assembly using the bellows of FIG. 4, the drive being adapted to rotate the spool-carrying shaft at a tensionresponsive variable speed;

FIG. 8 represents an enlarged view, partly in section, of a detail of the drive of FIG. 7;

FIG. 9 represents a fragmentary sectional view showing a modulating drive with a bellows-type slip clutch assembly in the manner of FIG. 7.'

Referring now to the drawings in detail in which like numbers designate like members throughout the several FIGS. it is to be noted that in FIGS. 1 and 2 there is shown a processing tank 30 which although shown as being closed may be either open or closed at the top andv which in the illustrated embodiment carries an upper shaft 31 on which there are mounted a series of film spools adapted to transport or convey film for processing into and out of the tank in a helical array and in a continuous manner. A series of film transporting spools 32 of conventional construction are freely. rotatably and axially slidably mounted upon shaft 31, except for spool 32 farthest to the right which is freely rotatable only. This shaft itself is rotatably supported and retained by a bearing 33 mounted on a side wall or panel of processing tank 30, and is further supported within the tank by a depending bracket and bearing 34 near'which there is a banking collar 35 pinned to the shaft. While the first or film in-leading spool 32 is of conventional construction, the next adjacent spool to the left generally designated 36 which is fixed to the shaft may have a special surface in its central portion 37 upon which film is carried, at

cuts are of sufficient spacing and depth that as spool 36 is rotated the tread surface presented to the film causes the film to be more positively gripped and advanced.

Between spool 36 and the next leftward regular spool 32 there is a bellows slip clutch generally designated 38 which is described in detail in my Pat. application Ser. No. 578,768, filed Sept. 12, 1966, and now US. Pat. No. 3,475,945. Between successive regular spools 32 there are pairs of collars 39. Individually these collars may be formed as bosses on the spools, but preferably are independent elements and must in any case be free to move axially along shaft 31. The collars are so sized as to permit each spool 32 to rotate on shaft 31 essentially independently of the adjacent spools in the absence ofan axial compacting force on the spool array. A longitudinal or axial force may be applied to cause an increase in the frictional engagement of adjacent collars 39 with each other and with the adjacent spools including spool 36 and baking collar 35. Helical springs may be used in place of collars 39. Such springs would have a determined compressive bias, and as interspaced between the spools would provide a slightly resilient drive for the spools sequentially along the shaft.

In the lower portion of tank there is disposed an elevator generally designated 40 which includes a horizontal member 42 having an upturned end which supports one end of a shaft 43. The other end of this shaft is carried by a boss 44 extending laterally from a header 45. A series of spools 32 are likewise carried on shaft 43. This shaft may be thought of as a lower shaft in contrast to shaft 31 taken as an upper shaft, and in the embodiment of the present invention shown in FIGS. 1 and 2 may be considered a dead or nonrotating shaft with spools 32 which it carries turning freely with respect to it. However, if particular circumstances such as film strength make it desirable shaft 43 could be mounted in bearings in support 42 and header 45, and spools 32 could be attached to the shaft or could be left free turning with the shaft itself either having or lacking a power drive. All of these arrangements are known to the prior art and no novelty is ascribed thereto except as the modulating drive of the present invention is associated with them and adapted to accommodate the variable operating factors found with these various film transport mechanisms.

Referring in particular to FIG. 2 it is to be noted that the right-hand side of elevator assembly 40 includes a channel element 47 mounted on the inner surface of tank 30. This element is shaped and sized to engage and retain within U- forrned leg end portions a set of our rollers 48 arranged in upperand lower pairs. These rollers are freely rotatable upon transverse shaft projections 49 carried on each end of header 45, and are sized to be freely movable up and down in the leg end portions of the channel element. Correspondingly, boss 44 is sized and located on header to be freely movable in the opening between the leg ends of channel 47. Elevator assembly 40 is weighed appropriately either integrally or by external attachment for any given processing circumstance of the film, full liquid immersion, exposure to liquid spray, exposure to a drying atmosphere, etc., to provide a proper basic tension in the film wound helically between and around the spools on upper and lower shafts 31 and 43, as the film extends and is transported through the whole processing apparatus.

' Referring to both FIGS. 1 and 2 it is to be noted that a control rod 50 extends upwardly from elevator assembly 40. This rod passes freely through the top panel of tank 30, and at its upper end is operatively engaged with a modulating drive flow control valve generally designated 52. This valve is more fully described in connection with FIG. 3. It is to be noted particularly, however, in connection with FIGS. 1 and 2 that as the tension in film being transported over the various spools increases the elevator assembly 40 and control rod 50 are moved upwardly by action of the film, and as tension in the film is reduced the elevator assembly and the control rod are moved downwardly by gravity.

Referring next to FIG. 3 it is to be noted that modulating drive flow control valve 52 shown therein includes a housing 54 which encloses a contoured cylindrical spool 55 having tapered ends and a central portion 56 reduced in diameter. Lands or full diameter portions 57a and 57b respectively above and below reduced portion 56 are sized to a close sliding fit in the bore of housing 54 and act as gas or fluid seals therein. As shown, spool 55 is mounted on control rod 50 close to the upper end thereof so that as this rod is moved the spool attached to it is also moved in correspondence to the movement of the elevator, and thus in correspondence to the tension in the film as above described. In the modulating flow control valve of FIG..3 the upper end of rod 50 is threaded to accept a nut 58. which retains a compression spring 60 between itself and the top surface of housing 54, thus giving the elevator assembly a resilient suspension. Adjustment of nut 58 sets the elevator 40 at a final desired position considered to correspond to normal tension in the film and a given length of film in the tank at any one time.

In practice, the mount for valve 52 is preferably a bracket permitting gross vertical adjustment of the position of the valve and hence to a considerable extent of the elevator assembly, with fine adjustment of elevator position being effected by manipulation of nut 58.

A vent 61 of determined size is provided in the sidewall of housing 54. As shown, this vent is enlarged for the purpose of illustration. Opposite this vent there is a flow connection opening 62 for passage of pressurized fluid or pull of vacuum. A pipe or tube 63 as seen in FIG. 1 leads from opening 62 to diaphragm slip clutch 38. In the lower portion of housing 54 there is an inlet opening 64 to which is connected a pipe 65 as shown in FIG. 1 which is further connected at its distant end to a source of fluid under pressure. In the upper portion of housing 54 there is an outlet opening 67 to which is connected a pipe 68 which is further connected at its distant end to a vacuum source or system. As valve spool 55 is carried upwardly by elevator rod 50 on account of increased film tension its lower land 57b is moved past opening 62. Fluid under pressure entering port or opening 64 then flows through opening 62 and pipe or conduit 63 to slip clutch 38 so as to speed up the rotation of the spools on upper shaft 31 in a manner described in my Pat. application Ser. No. 578,768, filed Sept. 12, 1966 and now US. Pat. No. 3,475,945. This speedup causes more film to be present in the tank at a given time thereby reducing the tension in the film. As the tension is decreased the elevator is allowed to descend carrying spool 55 downwardly until upper land 57a passes opening 62 placing clutch 38 in communication with a source of vacuum through opening 67. This causes a slowing down of the upper shaft spools and an increase in film tension. The foregoing operation cycle is more fully described in conjunction with the detailed description of the slip clutch in my patent application just mentioned.

Referring next to FIGS. 4, 5 and 6 there is shown a bellowstype slip clutch 109. As is brought out in greater detail in connection with the description of FIGS. 7, 8 and 9, this clutch functions in the first instance to modulate the speed of upper shaft 31 itself rather than the speed or speeds of the several spools upon this shaft. In the assembly of clutch 109 a collar 110 is attached to shaft 31 by means of setscrew 111. A flat plastic thrust bearing 112 which is free on shaft 31 and adjacent collar 110 partially encloses a metal washer 113 which is also free on the shaft. This washer lies adjacent a second free flat plastic thrust bearing 114. The plastic bearings 112 and 114 are preferably of Teflon or another material having a low coefficient of friction, while metal washer 113 is preferably of nonmagnetic stainless steel. A double bellows member 115 preferably made of rubber or other fluid-retaining resilient material may be molded or otherwise made of one piece or may be molded of two pieces. When of two pieces the bellows includes inner and outer generally U-shaped portions, the center part of each of which is partially folded upon itself. The bellows is provided with at least one fluid flow opening through one of the sidewalls to the interior cavity of the bellows, this opening, not shown, being located to mate with a similar opening in a bellows retaining means described below. The side walls of the molded bellows are clamped in place by means of two retaining rings 116 shown in detail in FIG. 5. Each ring 116 is characterized by tapped holes 117 which may be four in number. Between the holes 117 there are springretaining hooks 118 which are small metal tabs bent into a flattened, or thin channel shape as shown in section in FliG. 6. One end of each tab 118 is affixed to its base ring at point 119, with the tabs other end being bent down close but not attached to the face of the ring. Also to be noted in ring 116 in FIG. 5 is a fluid flow opening 120 which is provided in at least one of the rings 116 of a given clutch assembly 109 for alignment with the aforementioned opening in bellows 115 so that a tube or conduit constituting a fluid flow conductor from the interior of the bellows element of the slip clutch may be attached-to the flow connection opening of one of the valves 52, 69, described above. A pair of circular metal end members 121 provide rigid side supports for bellows 115, these end members having clear holes through the n for the passage of fillister-head cap screws 122 seen on the left-hand side of FIG. 4 and flat head screws 123 seen on the right-hand side in FIG. 4 which are threaded into holes 117 in rings 116 whereby these rings, the bellows, and the end members are clamped together. Also attached by means of flat head screws 123 is a pressure plate 124 which is preferably made of Teflon and is both free turning and free sliding with respect to shaft 31. A bearing 125 which also is preferably made of Teflon is pro vided to carry the bellows assembly including end members 121 and pressure plate 124 on shaft 31. This bearing preferably has a press fit within one of the end members and a free turning fit on shaft 31.

Collar 110 provides a stop reference so that all expansive movement generated by pressure applied to the interior of double bellows 115 causes pressure plate 124 to move outwardly or to the right. Likewise, when vacuum is applied to the interior of the bellows the pressure plate is drawn back leftwardly. As the action or movement to be generated by the bellows, that is, its expansion and contraction needed to move pressure plate 124 into and out of operating position, need be and preferably is only very slight, urging or moving of the pressure plate to the left or retracted or nonoperating position by the application of vacuum to the bellows 115 is made positive and particularly made even by an assist provided in the form of springs 126. The ends of these springs are attached by means of hooks 118 to one of the bellows retaining rings 116 and extend and are attached to corresponding hooks on the opposite retaining ring. The bellows assembly of slip clutch 109 is maintained in a nonrotating condition by means of the tube or conduit connection to the fluid flow opening 120 or by a support or brace, not shown, similar to means used to keep bellows slip clutch 38 nonrotative.

Referring next to FIGS. 7 and 8 there i i shown a clutch and sprocket drive assembly 128 associated ith shaft 31 with one or more of the spools 32 being fixedly attached to the shaft and the rotational speed of the shaft itself being made responsive to the action of modulating drive flow control valve 52. The bellows-type slip clutch assembly 109 shown in FIG. 4 is used to receive signals from flow connection opening 62 of the control valve. As seen in FIG. 8 the face of pressure plate 124 is adjacent a metal carrier disc 129 which is axially but not rotationally movable with respect to shaft 31. A composition friction disc 130 is fixedly attached to and carried by disc 129. The right-hand side of the friction disc is adjacent a metal pressure plate 131 which is fixedly attached to a sprocket or gear wheel I32 mounted on bearings 133 to be freely rotatable with respect to shaft 31. The sprocket or gear wheel which is retained on the shaft by collar or snap ring 134 is driven at an essentially constant speed by a prime mover not shown. A tube or conduit 135 extends from the flow connection opening of control valve 52 to the opening in end member 121 of clutch assembly 109 in alignment with retaining ring flow opening 120.

A pressure signal transmitted to clutch assembly 109 from control valve 52 will move pressure plate 124 to the right pushing carrier disc 129 and friction disc 130 ahead of it with the friction disc coming to bear against pressure plate 131. This will generate at least some clutching action between sprocket wheel or gear 132 and shaft 31 with rotational slippage possibly taking place between disc 130 and plate 131, and such slippage definitely occurring between pressure plate 124 and carrier plate 129 because of the bellows portion of assembly 109 being restrained against rotation and carrier plate 129 being required to turn with'shaft 31. The greater the fluid pressure applied to the bellows portion of clutch assembly 109 from the control valve through conduit 135 the greater will be the clutching action generated at the opposing faces of friction disc 130 and pressure plate 131 until, in the limit, there is no rotational slippage between this plate and this disc and shaft 31 is being driven at an angular speed equal to that of sprocket wheel 132. Conversely, clutching action may be diminished or in the end entirely and rapidly destroyed by relieving the fluid pressure applied to clutch assembly 109 or changing the pressure signal from control valve 52 to a vacuum signal, all as determined by the vertical movement of elevator control rod 50 in response to varying conditions of tension in the film being processed.

The drive modulation system of the apparatus arrangement of FIG. 7 may be compared with that of the arrangement of FIG. 1 so far as intermediate effects are concerned, although it is to be understood that an ultimate result of modulation of the speed of spools around which the film is passing is achieved in each case. In the case of FIG. 7 as described just applied the rotational speed of shaft 31 is modulated up to a peak value of the speed of sprocket wheel gear rotational assumed to be turning at a constant speed, and the speeds of those spools 32 fixed to the shaft rise and fall with that of the shaft. In the case of FIG. 1, on the other hand, upper shaft 31 is assumed to be driven at a constant speed with spools 32 being freewheeling on it and with respect to each other in the absence of fluid pressure in bellows-type slip clutch assembly 38. As pressure is applied to this assembly from control valve 52 through conduit 63, however, the otherwise freewheeling spools 32 are compacted axially between the clutch assembly and banking collar 35, and this collar which is pinned to and turns with shaft 31 begins to impart some angular speed to these spools. With only light pressure transmitted to clutch assembly and only light packing of the spool array, there will still be discernable slip or difference in speed between spools 32 and the shaft, and indeed between various ones of the spools themselves. As clutch assembly 38 receives a stronger pressure signal, however, and the spool array is more tightly packed, both spool-to-shaft and spool-to-spool slip will decrease, and the rotational speeds of all of the spools will tend to approach that of the shaft. Contrarily, as a weaker pressure signal is transmitted from control valve 52 there will be more slip and a decrease in spool speeds.

Referring next to FIG. 9 there is shown a combination-type modulating drive actuated on a single upper shaft 31 which includes a bellows-type slip clutch and sprocket drive assembly 128 in the manner of FIG. 7, and a film transporting spool assembly 138 having a fluid-actuated film gripping and releasing means operating through holes in the spool surface in a manner disclosed in my Pat. application Ser. No. 578,768, filed Sept. I2, 1966, and now U.S. Pat. No. 3,475,945. Highand low-pressure or vacuum signals are transmitted to drive assembly 128 from a modulating drive flow control valve 52 just as shown in FIG. 7, while pipes or conduits 171 and 172 are joined to connections in block of spool assembly 138 for the supplying and withdrawing of fluid for film grip modulation purposes. These pipes may be considered to be part of a film processing liquid pumping circuit shown and described. i1. my patent application just mentioned. Flow through such a circuit may be regulated by a second valve 52, not shown, which may be actuated by an elevator control rod 50 separate from the rod which is illustrated or which may indeed be placed in tandem with the illustrated valve on the same control rod. The particular combination-type modulating drive shown in FIG. 9 is provided for purposes of example only, that is, for showing that the several particular drive modulation systems or means illustrated and described herein and also in my said Pat. application Ser. No. 578,768, filed Sept. 12, 1966, are amenable to use in combination. Combinations other than the one illustrated will suggest themselves to those skilled in the art with the particular combination used in any given case depending on the circumstances of that case such as preferred film speed and tension, coefficients of friction between the film and the spool surfaces over which it is running, fineness of control required etc.

In all of the preceding description it has been indicated that power drive to a filmspool bank is applied at the banks upper shaft 31. While the upper shaft is often the powered shaft, it is to be understood that lower shaft 43 may also be power driven. In this arrangement a power transmission shaft may be disposed vertically in tank 30, extending from above the top to close to the bottom thereof. At its upper end this transmission shaft may be connected to a prime mover through a spline coupling to allow the shaft to have vertical motion while at its lower end it is connected to lower film spool shaft 43 through bevel tears. A clutch responsive to signals from a control valve actuated according to the up and down movement of the elevator may be carried on the lower shaft so as to provide a modulated f drive to the lower shafts spools with reference to an assumed estzblished angular speed of lower shaft 43 itself. Further, it may iometimes be desirable to apply a power drive to both the upper and the lower shafts of a given film spool bank with each of these shafts and/or the spool arrays on them having clutch mechanisms associated with them which are energized responsively to the vertical movement of the elevator of this bank and/or another bank or banks.

Protection by Letters Patent of this invention in all its aspects as the same are set forth in the appended claims is sought to the broadest extent that the prior art allows.

I claim:

1. In association with a rotatable shaft a slip clutch assembly wherethrough said shaft may be driven, said assembly comprising (l) a pressure plate freely rotatably mounted on said shaft, said pressure plate being adapted for operative engagement with a prime mover, (2) a friction disc and carrier means therefor axially movably but nonrotatably mounted upon said shaft so that said friction disc may be moved into contact with said pressure plate, and (3) an annular bellows surrounding said shaft and within which said shaft is freely rotatable, said bellows being disposed to be expanded to exert thrust against said axially movable friction disc and its carrier means to urge them against and into frictional, clutching engagement with said pressure plate while itself having negligible frictional engagement with said friction disc and carrier means.

2. A slip clutch assembly according to claim 1 which further comprises at least one tension spring within said bellows and attached to opposite ends thereof, this spring tending to maintain the bellows in contracted condition.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. Dated December 8, 1970 lnventorw Victor Takata It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title page, column 1, line 10: for "L -P753 45" read --3, +?+,9 +5--. Regular text, column 1, line 5: for "3, +75,9h5" read --3, #7 +,9h5. Column 1, line 8: for "interval" read --of--. Column 1, line 61: for "of" (last word. in line) read --or--. Column 3, line 7: for "3, +75,9h5 read --3, +7 +,9'+5--. Column 3, line 1?: for "baking" read --banking-. Column 3, line &8: for "our" read. --four--. Column 3, line 55: for "weighed." read --weighted--. Column 1 line +3: for "3,'+75,9 I5" read --3, +,9 4-5-. Column 5, line 18: for "one of the valves" read --valve--. Column 5, line 18: cancel comma after "52". Column 5, line 19: cancel "69,". Column 6, line 30: for "applied" read --above--. Column 6, line 32: between "wheel" and. "gear" read --or--. Column 6, line 32: for "rotational" read. --l32--. Column 6, line 62: for "L V/5,9 5" read --3, &7L;,9 +5--. Column 7, line 23: for "tears" read --gears-- Column 7, line 26: cancel "1"".

Signed and sealed this 8th day of June 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

